> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpara.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Verify Signatures with Cosmos Libraries

> Verify message and transaction signatures using CosmJS

Verify signatures from signed messages to authenticate users or validate transactions using CosmJS.

## Prerequisites

<Card title="Setup CosmJS Libraries" description="Configure CosmJS with Para SDK first" href="/v3/react/guides/web3-operations/cosmos/setup-libraries" icon="gear" horizontal />

## Verify Signatures

Verify ADR-036 signatures using CosmJS crypto utilities.

```typescript theme={null}
import { useState } from "react";
import { fromBase64, toUtf8 } from "@cosmjs/encoding";
import { Secp256k1, Secp256k1Signature, sha256 } from "@cosmjs/crypto";
import { serializeSignDoc, makeSignDoc } from "@cosmjs/amino";

function SignatureVerification() {
  const [isValid, setIsValid] = useState<boolean | null>(null);

  const verifyADR036Signature = async () => {
    const pubkeyBase64 = "A08EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQ";
    const signatureBase64 = "..."; // Signature from signAmino
    const originalMessage = "Hello Para!";
    const signerAddress = "cosmos1...";
    const chainId = "cosmoshub-4";

    try {
      const pubkey = fromBase64(pubkeyBase64);
      const signature = fromBase64(signatureBase64);

      const signDoc = makeSignDoc(
        [{ type: "sign/MsgSignData", value: { signer: signerAddress, data: btoa(originalMessage) } }],
        { amount: [], gas: "0" },
        chainId,
        "",
        0,
        0
      );

      const serialized = serializeSignDoc(signDoc);
      const messageHash = sha256(serialized);

      const sig = Secp256k1Signature.fromDer(signature);
      const valid = await Secp256k1.verifySignature(sig, messageHash, pubkey);

      setIsValid(valid);
      console.log("Signature valid:", valid);
    } catch (error) {
      console.error("Verification failed:", error);
      setIsValid(false);
    }
  };

  return (
    <div>
      <button onClick={verifyADR036Signature}>Verify Signature</button>
      {isValid !== null && <p>Valid: {isValid ? "Yes" : "No"}</p>}
    </div>
  );
}
```

## Next Steps

<CardGroup cols={3}>
  <Card title="Sign Messages" description="Create signatures for verification" href="/v3/react/guides/web3-operations/cosmos/sign-messages" icon="signature" />

  <Card title="Execute Transactions" description="Send verified transactions" href="/v3/react/guides/web3-operations/cosmos/execute-transactions" icon="bolt" />

  <Card title="Query Balances" description="Check account balances" href="/v3/react/guides/web3-operations/cosmos/query-balances" icon="wallet" />
</CardGroup>